Consider a file currently consisting of 100 blocks. Assume that the File Control Block (or, the index block, in case of indexed allocation) is already in the RAM. Calculate how many disk I/O operations (“read block” or “write block”) are required for contiguous, linked, and indexed (single-level) allocation strategies, if the following conditions hold (In the contiguous allocation case, assume that there is no room to grow in the beginning, but there is a room to grow in the end. In the linked allocation case, assume that FCB stores pointers to the first and the last block of the file; note that if a block is added or removed at the front or the end of the file, then the corresponding pointer is to be updated in FCB, but, since FCB is in the RAM, it does not require additional I/O operations. Assume that the block information to be written to the hard disk is stored in RAM).
a. The block is added at the beginning
b. The block is added in the middle
c. The block is added at the end
d. The block is removed from the beginning
e. The block is removed from the end.
This question was answered before but they gave just the answers no explanation. Can someone explain how the numbers were derived?